Cam grinding apparatus



June 13, 1944. c. J. GREEN 2,351,502

CAM GRINDING APPARATUS Filed Sept. 2, 1942 4 Sheets-Sheet 2 CL.HEENCEJEREEN MLJfiik-n June 13, 1944. Q J GREEN 2,351,502

CAM GRINDING APPARATUS Filed Sept. 2, 1942 4 Sheets-Sheet 4 EL HEE/VCEJER EE/V muauwmmw Patented June 13, 1944 2,351,502 cm GRINDINGarraaa'ros Clarence J. Green, Worcester, Mass., asslgnor to NortonCompany, Worcester, Mass, a corporation of Massaclmsett ApplicationSeptember 2, 1942, Serial No. 456,975

Claims.

This invention relates to grinding machines and more particularly to acam grinding ma-' chine.

One object of thi invention is to provide a simple and thoroughlypractical grinding machine for grinding cams. Another object of theinvention is to provide a cam grinding apparatus in which a cam forimparting motion in two directions may be accurately ground. Anotherobject of the invention is to provide a cam grinding apparatus in whichthe cam being ground is moved longitudinally and laterally to accuratelyproduce a pre-determined cam contour. A further object of this inventionis to provide a cam grinding apparatus having a rock bar which isarranged for a simultaneous rocking about in axis and movedlongitudinally in an axial direction to grind a pre-determined camcontour. Other parts will b obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements. and arrangement of parts as will beexemplified in the structures hereinafter described, and the scope ofthe application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of variousembodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of a grinding machine embodying thisinvention:

Fig. 2 is a fragmentary plan view of the grinding machine shown in Fig.1 having parts broken away and shown in sections to clarify theillustration;

Fig. 3 is a fragmentary elevation showing the arrangement of the rockbar together with the work support and the master cams for controllingthe movements thereof;

Fig. 4 is a fragmentary staggered sectional view on an enlarged scale,taken approximately on the line 4-4 of Fig. l; and

Fig. 5 is a fragmentary detailed view showing the arrangement of therock bar.

A cam grinding machine as illustrated in the drawings comprising a baseI0 which serves as a support for a longitudinally traversable table II.The table II is supported on a V-way l2 and a flat way l3 formed on theupper surface of the base Ill. The table II is arranged so that it maybe traversed longitudinally along the base III by means of a manuallyoperable traversing mechanism comprising a hand wheel 14 which issupported on the outer end of a shaft ii. .A gear l6 is mounted on theinner end of the shaft I5 and 55 meshes with a gear l'l mounted on arotatable shaft I! which is Journaled in suitable bearings (not shown)in the base end. The shaft II also supports a gear I! which meshes witha rackbar depending from the under side of the table I I.

A stop mechanism is provided for locating the table II in apre-determined fixed position for a grinding operation. The stop lug isfixedly mounted on the base l0 and is arranged to be engaged by a pairof adjustable stop dogs 26 and 21. The stop dogs 26 and 21 are supportedby T-slot 28 formed in the front edge of the table II. The stop dogs 26and 21 are each provided with an adjustable stop screw 29 and 30respectively by means of which the table I I may be precisely located toposition the work piece to be ground in a pre-determined position withrelation to the grinding wheel.

The base II) also serves as a support for a transversely movable wheelslide 32 which is arranged to slide transversely relative to the base 10on a V-way 33 and a flat way 34. The wheel slide 32 supports a rotatablewheel spindle 35 in journal bearings (not shown). A grinding wheel 36 ismounted on one end of the wheel spindle 35 and a driving pulley 31 ismounted on the other end thereof. The driving pulley 31 is connected bya driving belt 38 with a suitable source of power, such as, for examplean electric motor (not shown) mounted on the upper surface of the wheelslide 32.

A wheel feeding mechanism is provided for moving the grinding wheel 38transversely comprising a rotatable feed screw 40 which is supported inthe bearing (not shown) in the base ID. A half nut 4| depends from theunder side of the wheel slide 32 and meshes with the feed screw 40. Thefeed screw 40 is provided with an integral reduced cylindrical portion42 which projects from the front of the machine base. A gear 43 imounted on the outer end of the feed screw shaft 42 which in turn mesheswith a gear 44. The gear 44 is mounted on the inner end of a rotatableshaft 45. A manually operable feed wheel 46 is mounted on the outer endof the shaft 45. A micrometer feed adjusting mechanism 41 is providedwith a stop abutment 43 which is arranged to engage a pivotally mountedstop pawl 49 which is in turn pivotally supported in the front of themachine base ill. It will be readily apparent from the foregoingdisclosure that by a manual manipulation of the feed wheel 46, thegrinding wheel 36 may be moved transversely either toward or from thework supporting table II as desired. By adjustment of the micrometertrunnions II and I2 feed adjustment 1, the grinding wheel Il maybemovedintoaprecisepositiontogrindthe work piece to the desireddiameter. For further details of this feeding mechanism reference may behad to the expired U. 8. Patent to C. H. Norton No. 762,838 dated June14, 1904,

The work supporting table II serves as ampport for a rock bar IO. Therock bar ll is provided at its opposite ends with a pair of axiallyaligned trunnions BI and I! which are journaled in bearings formedwithin the brackets l3 and N projecting upwardly from the work table II. The rockbar II is arrangedsothat itmayberocked about the trunnions IIand I! and is also arranged so that it may be moved longitudinally: thatis in an axial direction with respect to the bearing rotation of a workpiece to impart a combined transverse and longitudinal movement to awork piece being ground in a manner to be hereinafter described.

The rock bar I. is provided with a rotatable head stock or master camspindle 5! which is journaled in upwardly projecting brackets N and 51which are formed integral with the rock bar II. The spindle 55 isprovided with a work center is which engage and supports one end of awork piece 59 to be ground. A rootstock Cl is adjustably supported onthe rock bar 50 and is provided with a footstock center 6| which engagesand supports the opposite end of the work piece 5". The headstockspindle I is also provided with a face Plate I having a driving pin 63which is arranged to drivingly engage a work dog 84 mounted on/oradjacent to the left hand end of the work piece ll. The headstock ormaster cam spindle I5 is provided with a master cam 85 which is arrangedtoengage a master cam roller 8.. The master cam' roller '6 is supportedon a rotatable shaft 01 which is in turn rotatably journaled in bearings(not shown) in the brackets I and II which are formed integral with thebrackets I! and 51 respectively.

A motor drive is provided for the headstock or master cam spindle 55comprising an electric motor III which drives through a gear reductionunit contained within the casing H to rotate a universal joint 12 whichconnects with the left hand end of the spindle 55 (Fig. 2). It will .bereadily apparent from the foregoing disclosure that a rotary motion ofthe master cam or headstock spindle 55 will transmit a rotary motion tothe workpiece 59. At the same time a rotary motion is imparted to themaster cam 65 which is yieldably maintained in operative contact withthe roller 68 so that the motion of the cam 65 will impart a rockingmotion to the rock bar It and thus cause the axis of the work piece I!to move towards and from the periphery of the grinding wheel 36 togenerate a pre-determined contour on the work piece 59 being ground.

In order to grind special cam shapes having both a transverse as well asan axial movement to be imparted thereby, a suitable mechanism isprovided to simultaneously impart an axial movement to the rock bar illduring its oscillation. This mechanism may comprise a master cam 15having a face cam generated thereon. A master cam roller is provided andis rotatably supported on a shaft I1 which is supported within a casingor frame II surrounding the headstock of the machine. A compressionspring III is interposed between a flanged plate ll fastened to thebracket 54 at one end and a collar 82 adjustably connected by a rod 03with the exertsapressuretendingtomcvetherockbar in a direction towardthe right (Figs. 1, 2, 3) so as to maintain the operative side face ofthe cam II in operative engagement with the master cam roller ll.

In order that the master cam roller ll may be maintained in apre-determined relationship with the cam ll during the transverseoscillation of rock bar II, the shaft I1 is preferably supportedtrunnion 52 in a manner so that the spring 8| 7 by two pairs of rollersII and I! and 81 at one end and '8, IO, and I. at the other end. Theshaft 11 thus supported is free to move in a transverse direction. Inorder that the shaft may move in timed relation with the rock bar 50, astrap ll surrounds a portion of the master cam or headstock spindle II.The strap ll connects by a stud I! with the end 01 the shaft 11. It will.be readily apparent from the foregoing disclosure that when the rockbar II is oscillated about its pivotal axis by means of the cam BI andfollower It, the strap II being rotatably supported on the spindle IIwill move the master cam roller I8 transversely so as to maintain it ina pre-determined relationship with the operative face of the cam ll.During the rotary motion of the spindle II to impart a transverseoscillation of the rock bar I, the cam I! will in turn impart asimultaneous longitudinal movement to the rock bar so that a cam facehaving the surfaces Ill and III to be ground may be accurately generatedas desired. In order to maintain the master cam II inoperativeengagement with the master cam roll-' er II a tension springIll is contained within a casing Ill supported by a bracket Ill on theend of the headstock casing 18 (Fig. 2). The upper end of the spring I02is connected to the lower end of an adjusting screw I. The lower end ofthe adjusting screw is connected to a stud ll! which is pivotallysupported by a stud I carried by a bracket Ill. The bracket I01 is inturn pivotally connected by a stud I" with an arm III! which is formedintegral, with the rock bar 50. The right hand face oi the casing I03 isopen (Fig. 1) so that as the rock bar is moved in an axial orlongitudinal direction by the cam II, due to the pivotal connection atthe lower end of the spring Ill a constant tension will be exerted .bythe spring III uniformly to maintain the master cam ll in operativecontact with its follower roller I. v v

The operation of this improved cam grinding apparatus will be readilyappreciated from the foregoing disclosure. Assuming all of the parts tohave been previously setup, a work piece Is having cam faces I00 and Illto be generated is mounted in position on the work supporting centers 58and ii respectively with the work driving pin is in engagement with thework driving dog 64. The table Ii is then traversed longitudinally sothat the work piece II is in a desired and pre-determined relationshipwith the grinding wheel ll after which the table. dogs 20 and 21 arelocked in adjusted position. The table may then be precisely adjusted toafurther extent by manipulation of the stop screws 20 will generate thecam faces I and "H which are arranged to transmit transverse andlongitudinal movements. Wheel may be fed transversely to grind the facesI00 and IM to the desired and pro-determined extent by a manualmanipulation of the feed wheel 48.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

Iclaim:

1. In a cam grinding apparatus having a transversely movable rotatablegrinding wheel, a rotatable work supporting member including a rotatablespindle, means positively to rotate said spindle, a longitudinally andtransversely movable support for said work supporting member, meansincluding a cam on said spindle and a follower to impart a transversemovement to said work supporting member, independent means including asecond cam on said spindle and a second follower simultaneously toimpart a longitudinal movement to said work supporting member tofacilitate grinding an irregular cam face, a transversely movablesupport for said second follower, and means to maintain said latferfollower in a predetermined relationship with said second cam duringtransverse movement of said longitudinally and transversely movablesupport.

2. In a cam grinding machine having a transversely movable rotatablegrinding wheel, a rock bar which is pivotally supported about an axisparallel to the axis of the grinding wheel, a rotatable work support onsaid bar including a rotatable master cam spindle and a footstock, meansincluding an electric motor to rotate said spindle and work piece, meansincluding a master cam on said spindle and a follower to impart atransverse rocking movement to said bar, means including a second mastercam on said spindle and a slidably mounted follower roller which arearranged to impart a longitudinal axial movement to the rock bar, saidcams being shaped and timed to impart a combined simultaneouslongitudinal and transverse movement to generate an irregular cam face,a transversely movable support for said slidably mounted followerroller, and means to maintain said follower in a predeterminedrelationship with said second cam during oscillation of said rock bar.

3. In a cam grinding apparatus having a base, a transversely movablerotatable wheel thereon, a longitudinally movable work table on saidbase, means to locate and hold said table in a predemined grindingposition, a rock bar pivotally supported on said table, a rotatable worksupport on said rock bar including a rotatable spinnections between saidslide and said spindle whereby said latter follower is maintained in apredetermined relationship with said latter cam during oscillation ofsaid rock bar.

4. In a cam grinding apparatus having a base, a transversely movablerotatable grinding wheel thereon, a longitudinally movable work table onsaid base, means to locate and hold said table in a predeterminedgrinding position, a longitudi-* nally movable rock bar pivotallysupported on said table, a rotatable work support on said rock barincluding a rotatable spindle to support and rotate a work support,means positively to rotate said spindle, means including a cam on saidspindle and a follower to impart a rocking movement to said bar,yieldable means to maintain said cam in operative engagement with thefol-. lower, means including a cam on said spindle and a followersimultaneously to impart a longitudinal movement to said rock bar tofacilitate grinding an irregular cam face on a work piece, atransversely movable slide supporting said second follower, andconnections between said spindle and slide to facilitate maintainingsaid second follower in a predetermined relationship with the second camduring the rocking movement of said bar.

5. In a cam grinding apparatus having a base, a transversely movablerotatable grinding wheel thereon, a longitudinally movable work table onsaid base, means to locate and hold said table in a predeterminedgrinding position, a longitudinally movable rock bar pivotally supportedon said table, a rotatable work support on said rock bar including arotatable spindle to support and rotate a work support, means positivelyto rotate said spindle, means including a cam on said spindle and afollower to impart a rocking movement to said bar, yieldable means tomaintain said cam in operative engagement with the follower, meansincluding a second cam on said spindle and a second followersimultaneously to impart a longitudinal movement to said rock bar,yieldable means to move said rock bar longitudinally in one direction tomaintain said second cam in operative contact with its follower, atransversely movable slide supporting said second follower, andconnections between said spindle and slide to facilitate maintainingsaid second follower in a predetermined relationship with the second camduring the rocking movement of said bar.

CLARENCE J. GREEN-

